Fluid-actuated percussive tool



Patented May 21, 1929.

UNITED STATES PATENT oFFrcE;

FRED M. SLATER, OF EASTON, PERI-,5! SYLVAN IA, ASSIGNOR TO INGERSOLL-RAND COM- PANY, or JERSEY CITY, NEVVJERSEY, A CORPORATION or NEW JERSEY.

FLUID-ACTUATED PERCUSSIVE TOOL.

Application filed May 2, 1927.- Sam Ila-188,198.

This invention relates to pneumatic hammer tools, butv more particularly to the arrangement of the handle and throttle valve for tools of this type. V

The object of the invention is to enable the operator to conveniently control the admission of pressure fluid to the tool by such pressure on the handle of the tool as is ordinarily applied thereto to hold the tool against the Work.

Other objects will be in part obvious and in part pointed out in the following description taken in conjunction with the accompanying drawings, in which Figure 1 is an elevation partly in section of the rearward end of a pneumatiotool equipped with a handle constructed in accordance with the practice of the invention,

Figure 2 is an end view of the handle, and

Figure 3 is a side view in elevation of the handle.

Referring to the drawings, the invention is shown as applied to a pneumatic hammer tool, such as a coal pick, comprising a cylinder A having exterior threads B at its rearward end in engagement with a threaded recess C of a handle D. In the present instance the front end or sleeve portion E of the handle D is provided with a longitudinal slot F in one side and a bolt G extends transversely through the side of the hood E for clamping the hood firmly to the rearward end of the cylinder.

Disposed on the rearward end of the cylinder A is avalve seat H in the form of a plate which lies near the rearwardend of the recess C and, in this instance, has inclined seating surfaces J and K for a valve L. The valve L is in the form of a flat plate like disc adapted to rock on the apex formed by the inclined surfaces J and K for controlling rearward and front inlet passages 0 and P respectively.

ny suitable means may be provided for holding the valve L against lateral displacement. In the present instance a pin Q, seated in the plate H and extending through an aperture R in the valve L is provided for this purpose. I

As will be observed, the plate His of less thickness than the depth of that portion of the recess C rearwardly of the threaded portion, thus leaving a space which forms a valve chamber S wherein the valve L may oscillate 7 Pressure fluid operating tlietoolmay be conveyed from a suitable source of supply (not shown) by means of a hose orsupply line (not shown)v which may. be connecte to a connection T in a rearwardlyextending connection T leads a passage V which communicates at its inner end with a throttle valve chamber W. Communication between the throttle valve chamber WV and the valve chamber 8 is in this instance afforded by arm U carried by the handle D. From the passages X and Y, the passage X preferably 3 being formed coaxially with the throttle valve chamber W whilethe passage Y in this instance extend-s laterally of the passage 'X.

At the inlet opening of the passage X is formed a valve seat Z upon which is seated a throttle valve 6, in the form of a ball, normally held on the seat Z by a compression spring 0 seated with itsouter end against a plug d which forms a closure for the chamber W.

Secured pivotally to the rearward end of the arm U is a handle grip 6 whereby the hammer tool may be manipulated. The handle grip e in this instance has a lateral leg f which extends slidably into a slot 9 formed by rearwardly extending prongs h carried by the handle D, preferably diametrically opposite to the arm U.

The free end of the leg 7 has an inclined surface j adapted to seat on an end k of the rod 0 disposed slidably in a bore 9 in the handle and abutting with its inner end the throttle valve 1). In order to protect the inclined surface j against such wear which ordinarily occursin devices of this character, a plug 9 is inserted inthe end of the leg f to form a removablie wearing surface between the leg f and the r0 0.

Suitable means are provided for limiting the degree of movement of the handle grip e. This is accomplished in the present instance by means of a pin 1' seated with its ends in the prongs h and extending slidably through an oblong transverse slot 8 in the leg The slot 8 maybe of suchlength that its ends will act as abutments for the pin 7". a

The operation of the device is as follows:

lot

.ii sure fluid controlling means.

the inclined surface 7' against the rod 0 through Which the movement of the handle grip e will be transmitted to the throttle valve 6, thus opening the throttle valve and admit ting pressure fluid from the passage into the valve chamber S, from whence it Will be dis tributed by the valve L to the cylinder A. After the drilling operation has been completed, pressure against the handle grip 6 may be relaxed and the spring 0 expanding against the throttle valve 6 will close said throttle valve and at the same time restore the handle grip e to its initial position.

This invention is particularly advantageous When applied to hammer tools of the coal pick type, since these tools are frequently used in narrow drifts Where there is little head room and where it is frequently diflicult for the operator to manipulate independent pres- Another desirable feature of the present invention is that the handle may be of comparatively smooth exterior form thus eliminating any undesirable projections which, during the operation of the tool, frequently interfere With the best operation thereof. By disposing the throttle valve Z) and the associated elements in the positions indicated, the height of the handle may be held to a minimum and the total weight of the tool may thus be considerably decreased Without sacrificing the necessary strength.

I claim:

A fluid actuated percussive tool comprising a cylinder, a reciprocating piston in the cylinder, a distributing valve at the rearward portion of the cylinder, a handle forming a back head adapted to be secured to the barrel, said handle having a body portion provided with rearwardly extending prongs at one side, a handle grip pivoted at one end on the body portion, aleg on the handle gripislidable between the prongs and having a trans verse slot, an inclined surface on the free end of the leg, a spring pressed throttle valve in the body portion, a rod transversely slidable in the body portion and interposed between the inclined surface and the throttle valve for transmitting movement of the handle grip to the throttle valve to open said throttle valve, and a plug in the leg to protect said leg against wear occasioned by the rod. i

In'testimony whereof I have signed this specification.

FRED M. SLATER. 

